The extraction of high-resolution data from helically symmetric structures and the interpretation of molecular maps of helical structures in terms of docked atomic models are frontiers in structural cell biology. We propose to develop algorithms to extract higher resolution data from images of helically symmetric structures, to extend our capabilities for docking atomic models of components into molecular maps of complexes of these complexes of these components, to produce a complete set of programs that incorporates state-of-the-art algorithms into a user-friendly package that will be distributed to the EM community, and to produce a clonable, gold-binding tag for electron microscopy. The state-of-the-art developments will be applied (in separately funded studies") to the bacterial flagellae and to the actin cytoskeleton. In particular the high resolution methods will be used to extend the resolution of the hook and filament from 10A to 4 resolution and of actyomyosin from 20 to 10 A. The docking procedures will be applied to 2D bundles or rafts of actin and actin bundling proteins such as fimbrin, villin and aldolase. The aim is to characterize the polymorphism and to derive docked atomic models for the actin bundles.